Climate Change: Land use emissions from traded agricultural products such as beef and palm oil account for a quarter of total world emissions, according to a new report.
The Climate Change Crisis: The hamburger you just ate may be more carbon-dense than you think. Researchers for the first time measured the increase in greenhouse gas emissions contained in the international trade in certain agricultural products such as beef that lead to deforestation.
Such “land use emissions” account for about 25% of global greenhouse gas emissions and occur mostly in poorer countries that export food to the United States, Europe, China and other industrial areas, according to a peer-reviewed paper published 6 May in the journal Science. “These land use emissions are large enough to threaten international climate goals even if fossil fuel emissions are drastically reduced,” the paper said.
Land use emissions come from agricultural production, such as methane released by cattle grazing, as well as greenhouse gases emitted from clearing forests for agricultural purposes such as creating pasture for livestock. The researchers found that three-quarters of emissions from international agricultural trade come from land use change. A model they created based on trade and agriculture data found that between 2004 and 2017, land use emissions in international trade increased 14%.
“The issue of land use change needs to be at the forefront and center of our radar,” said Steven Davis, co-author of the paper and professor of Earth systems science at the University of California at Irvine.
Davis and other scientists say rich countries outsource land use emissions to countries like Brazil and Indonesia. “In places like the US or Europe, there’s been very little land use change for agriculture because we were deforesting early in our history,” Davis said.
Timothy Seachinger, senior research fellow at Princeton University and technical director of the World Resources Institute’s food program, studies agricultural land use and climate change. He said policies designed to lower greenhouse emissions from transportation in developed countries increase land use emissions as forests are converted to grow crops for biofuels.
For example, the European Union’s plan to reduce emissions by at least 55% by 2030 hinges in part on expanding biofuels. That, he said, would require the conversion of one-fifth of the EU’s agricultural land from food to fuel unless crops for biofuels were imported.
“Europe has shifted a lot of its land use for agriculture to other countries,” said Searchinger, who was not involved in the land use emissions study. “We have a massive increase in demand for food and policymakers have supplemented it with a bioenergy mandate.”
The paper sends an important message about being responsible for land use emissions, he added. “People think it’s just some kind of nefarious activity by developing countries cutting down forests,” Searchinger said. “What is driving this is for product demand” in the US, Europe and China.
Davis and his colleagues determined that cereals and oil crops, such as soybeans and palm oil, accounted for 45% to 55% of land use emissions in international agricultural trade between 2004 and 2017. Cattle, pigs, and other animals represent 14% to 19%. emissions while fruits and vegetables are responsible for less than 8%.
Searchinger said the government could lower land use emissions by adopting policies to reduce dependence on biofuels and reduce demand for meat. Imposing tariffs on products with high land use emissions is another option, Davis said.
The obscurity of food supply chains can make it harder for consumers to avoid carbon-rich foods, Davis said. Palm oil, for example, is a ubiquitous ingredient in many foods, from bread and margarine to cookies and ice cream, and its cultivation has resulted in widespread deforestation in Indonesia.
“If you take a box of brownie mix that has palm oil in it, it doesn’t say where the palm oil is grown,” he said. “People are kind of tired of all the things they are trying to monitor with their consumption. It would be better to take a systematic approach to influencing the price of goods” with high land use emissions.